X10 project #1

 The motion sensor runs on 4 x AA batteries but I have converted mine to run on 5volt DC from a power source. I hate to change batteries and it's really rough on batteries to be outside in the cold weather. Murphy's law says that the batteries will go dead just when you need them. My experirnce with 3 of these units is that the batteries last a long time, 6 to 9 months if I remember correctly.

The motion sensor and the base unit have 11 channels of radio frequencies that you can adjust with a rotary dial. You set the motion sensor and the base unit to the same channel. In normal operation, the base unit receives a radio signal from the motion sensor and then can turn on a lamp and/or ring a chime.

 I have 3 of these units on my property, all set to different channels so they do not interfere with each other. My neighbor also has one and we agreed on the channels we would each use. He's really not close enough to me to set off my base units but we picked our channels anyway.

The base unit has two slide switches. You can set one switch to chime when motion is detected. The four switch settings are volume level High-Med-Low-Off (no chime).  The other switch controls the lamp socket output on the side of the unit. You can set this switch to Auto (Lamp on and off with motion) - Lamp on (lamp on full time) - Off (lamp never on)

 The base unit has a relay inside that is turning on and off the 120VAC to the lamp socket. We are going to slice a printed circuit board trace and interrupt the 120VAC from reaching the relay switch contacts. There is also one small feedback resistor that we are going to unsolder one end on, because it feeds back 120VAC from a 120VAC contact point.

 Once you cut off the 120VAC supply to the relay switch contacts, you end up with a simple set of switch points that open and close with no voltage on the relay switch contacts. The Powerflash unit has a mode that when the two contacts on the Powerflash are shorted out, it transmits an X10 signal onto your power lines and then all sorts of things are possible from there. The simple set of relay switch contacts can now trigger the Powerflash contacts. The Powerflash is set to Input B and Mode 3

 I will also be removing the two female lamp socket plugs from the printed circuit board so that nothing can be plugged into them. There is still 120VAC going to these female jacks and so it's best to get rid of them for safety. I am using the lamp socket hole as an exit for my switch contact wires that go to the Powerflash unit. I'll probably forget 5 years from now why I can't plug anything into the base unit lamp socket. Having the wire sticking out of one hole may remind me. Removing the female jacks prevents me.  :)